The present invention related to filtration systems for aquariums. More particularly, it relates to an external filter system utilizing filter cartridges as the primary means of filtration.
External aquarium filters employing a filter cartridge are regularly used for the purpose of filtration and cleaning of aquarium water. The aquarium water is cleaned in part by mechanical removal of particulate fish waste. The chemical waste is removed by aerobic bacterial means. The filter cartridge provides a substrate for screening out particulate matter. The substrate also provides a surface on whic aerobic bacteria may live and adhere to.
When the cartridge eventually becomes clogged by trapped detrius and organic wastes, it must then be removed and cleaned or replaced by a new filter substrate. The time interval between changing the cartridge is dependant upon the quantity and size of fish as well as the flow rate of contaminated water through the filter. The physical size of the cartridge or the number of cartridges also determines the time interval.
In prior art devices such as U.S. Pat. Nos. 4,512,885 and 5,078,867, the cartridge size is limited by the depth and width of the filter assembly. The flow rate of this type filter is restricted by the filter cartridge area, and the cartridge needs to be replaced often. Only one filter cartridge can be placed in the filter chamber. The cartridge slides into tracks which are an intergral part of the filter chamber in the external filter and pump assembly. The tracks allow easy replacement of the cartridge when it needs to be replaced.